The primary objective of this project is to develop and test interactive microcomputer software for a self-reported dietary assessment instrument. The framework for dietary assessment is a stepwise food group selection and quantification of the respondent's usual (or time referenced) intake of specific foods within the groups selected. This project is aimed at solutions to problems of respondent burden, reliability, validity, and timeliness of data reporting through the application of microcomputer technology to an improved questionnaire design. The software to be developed in Phase I will have the following features which are marked improvements over current methods: Queries including quality estimations are presented to respondents in a uniform way. Since respondents interact with personal computers directly, interviewer variability and possible bias are eliminated. Coding and quantity conversions are computer generated, thereby eliminating a tedious,, time consuming process, as well as coding errors. Frames of questions are modular, and can be presented to respondents in a selective fashion, depending on study needs and respondents' attention span. The time to complete a full dietary assessment will take no more time than a good diet history interview (about 1-1 1/2 hours); however, the staff time spent in interviewing is virtually saved, since the staff will merely assist the patient to interact with the computer. Thus, the respondent burden will remain about the same in total response time, but as noted above, responses can be scheduled modularly to prevent fatigue. The above features will be fully developed and tested in Phase II of this proposed project.